zerohash europe B.V. holds custody of your crypto-assets through its affiliate stichting derdengelden zerohash, which is a Netherlands-registered Third Party Assets Foundation (in Dutch: Stichting Bewaarinstelling). You can find further information about how your crypto-assets are held in the User Agreement between you and zerohash.
Trading, settlement and custody services in connection with crypto-assets through IBKR platforms are provided by zerohash europe B.V.